Ballpoint pen



FIG. 1 is a front view of a ballpoint pen showing my new design, a rear view being symmetrical to the front view;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a front view thereof in a state that a clip is opened;

FIG. 7 is a front view thereof in a state that a tip of the pen is projected to a use position; and,

FIG. 8 is a perspective view thereof. 

The ornamental design for a ballpoint pen, as shown and described. 